An uninterruptible power supply or uninterruptible power source (UPS) is an electrical system that temporarily supplies electrical power to a load, such as a computer system, when the input power source, typically utility power, powering the load is disrupted, in order to maintain reliable operation of the load. A UPS system is typically used to protect hardware, such as computers, data centers, telecommunications equipment, medical equipment, and other types of mission critical electrical equipment, where an unexpected power disruption could have very serious adverse consequences.
UPS systems have become an essential part of any reliable computer system, to prevent the loss of critical data during an over-voltage, under-voltage, or complete loss of voltage event. Over the years, UPS systems have become increasingly reliable to the point where their performance has become rather generic, shifting the competition to efficiency. This is especially true for high-power UPSs, and specifically in large data centers. In these installations, power consumption has become the major cost, so maximizing power efficiency is increasingly important, both to reduce the direct cost of the electricity consumed, but also to reduce the size and cost of the cooling systems needed to keep the computer equipment operating in a reliable temperature range.
UPS use has grown as the UPS has become an essential part of any reliable computer system, to prevent the loss of critical data during over-voltage, under-voltage, or complete loss of voltage events. Over the years, the UPS has become increasingly reliable to the point where UPS performance has become secondary to efficiency. This is especially true for high-power UPSs, and even more true with regard to mission critical UPSs used in large data centers. In these installations, power consumption is such a major cost, maximizing UPS power efficiency has become increasingly important, both to reduce the amount of electricity consumed, but also to reduce the size and cost of cooling systems needed to keep the computer equipment operating in a reliable temperature range.
Unfortunately, there is a limit to how much UPS power consumption can be reduced because they use semiconductor power switching arrangements, typically SCR switches, which must remain powered during UPS operation.
What is needed is needed is a UPS system that overcomes at least some of these drawbacks. What is also needed is a UPS system that is more efficient, more reliable and more cost effective.